Microstructure Evolution and Mechanical Properties of Rheo-Squeeze Cast Mg-9Al-1Zn Alloy by Experiments and Thermodynamic Calculation

Microstructure evolution and mechanical properties of Mg-9Al-1Zn alloy produced by rheo-squeeze casting (R-SQC) were investigated. It was revealed that R-SQC has produced high integrity castings with fine and uniform microstructure, diminished defects, and improved mechanical properties. The solid content in semi-solid slurry determined the grain size of α-Mg phase, the volume content, and distribution of β-Mg₁₇Al₁₂ phase, and predominantly controlled the mechanical properties. A two-stage thermodynamic calculation procedure to analyze R-SQC has been developed, and the solidification path and phase formation of Mg-9Al-1Zn alloy in R-SQC were discussed deeply.